A volcano quiet for more than a century erupted in a New Zealand national park, spreading thick ash for several kilometres and causing some residents to evacuate their homes. Some domestic flights were cancelled Tuesday.

Mount Tongariro spewed ash and rocks for about 30 minutes late Monday night after a few weeks of increased seismic activity. It didn't cause any injuries or damage in the sparsely populated central North Island region. Tongariro National Park has three active volcanos, is a popular tourist destination and was the backdrop for many scenes in the "Lord of the Rings" movies.

Some residents left their homes as a precaution, and authorities temporarily closed roads. National carrier Air New Zealand cancelled or delayed domestic flights to towns near the mountain, though by Tuesday afternoon, it said it was resuming service to locations where the ash cloud had cleared. No international flights were affected.

Police said a witness to the eruption described flashes and explosions followed by a cloud of ash coming from a hole in the north face of the mountain. The Department of Conservation said three hikers were staying in a hut on the opposite slope of Mount Tongariro when it erupted but they walked out of the area safely.

Steve Sherburn, a volcanologist at the government agency GNS Science, said the eruption spread a layer of ash several centimetres thick for several kilometres. He said he'd heard reports of ash travelling on wind currents to coastal towns 100 kilometres away. He said the eruption was likely caused by steam pressure building within the mountain.

The nation's civil defence ministry said eruption activity was subsiding though it still urged caution for people who were in the vicinity of the volcano. The park has closed hiking trails and sleeping huts on the mountain for now.

New Zealand is part of the Pacific's "Ring of Fire" and has frequent geothermal and seismic activity. However, the last verified eruption of Mount Tongariro occurred in 1897.

Sherburn said it was too early to determine whether the latest eruption was the start of a renewed cycle of activity.